Photoprocessing vessels such as disclosed in a U.S. Pat. No. 5,339,131 utilize a rack and tank arrangement in which a rack is inserted within a tank to form a low volume processing vessel. That is, when the rack is inserted within the tank a space is formed therebetween for the passage of photosensitive material therethrough. The processing path as shown in U.S. Pat. No. 5,339,131 and other rack and tank arrangements are usually U-shaped and have a downward portion and an upward portion.
In cases where an emulsion side of the photosensitive material in the processing path faces the rack of a rack and tank arrangement, one method of supplying processing solution to the processing path involves providing a tubular member or nozzle assembly within the area of the rack. The tubular member or nozzle assembly includes openings or slots on opposing sides which provide processing solution to the downward portion and the upward portion of the processing path. However, there is a drawback with this arrangement in that processing solution supplied to the nozzle assembly will exit through slots at the inlet end of the nozzle assembly with a greater pressure than processing solution which exits at slots at the downstream end of the nozzle assembly. This provides for an uneven processing of photosensitive material which passes through the processing path in front of the slots of the nozzle assembly.
U.S. Pat. No. 5,313,243 suggests a narrowing of a processing path which leads to a slot nozzle. However, in the structure of the arrangement disclosed in U.S. Pat. No. 5,313,243, the openings or slots are only on one side of the slot nozzle. In a rack and tank arrangement as discussed above, the nozzle assembly supplies processing solution from opposing sides to both the upward and downward portion of the processing path. If the nozzle assembly were narrowed on one side, the result would be that the width of the processing path at the specific location where the nozzle assembly is narrowed (upward or downward portion) would be changed. This results in a non-uniform processing path along the upward and downward portions and would make it difficult to provide for uniform processing along both the upward and downward portions.
Additionally, in rack and tank arrangements which utilize a nozzle assembly in the area of the rack, at the start of a processing cycle when photosensitive material is first introduced into the processing tank, the photosensitive material first enters the downward portion of the processing path. As the photosensitive material passes in front of openings or slots of the nozzle assembly which face and supply processing solution to the downward portion of the processing path, there is no photosensitive material in the upward portion of the processing path. Therefore, the openings or slots of the nozzle assembly which supply processing solution to the upward portion of the processing path will not be facing photosensitive material. At this specific point of processing, some of the processing solution which flows in the nozzle assembly will be urged by the presence of the photosensitive material in the downward portion of the photoprocessing path out of the slots which face the upward portion of the photoprocessing path where no photosensitive material is present. This reduces the pressure of the solution applied to the photosensitive material through the slots which supply processing solution to the downward portion of the photoprocessing path. This can also occur at the end of a processing cycle when the photosensitive material is present in the upward portion of the processing path and not in the downward portion.